1. Field of the Invention
The present invention relates to a head suspension and a load beam for supporting a slider that reads and writes data to and from a hard disk in a hard disk drive installed in an information processor such as a personal computer. The present invention also relates to a method of manufacturing the load beam.
2. Description of Related Art
A hard disk drive used for an information processor such as a personal computer incorporates a hard disk that is read and written with a slider attached to a head of a head suspension. The hard disk is rotated at high speed and the slider is slightly raised from the surface of the hard disk and is moved across tracks of the hard disk, to write and read data to and from the hard disk through a transducer. The slider is attached to the head suspension so that the slider may float off the surface of the hard disk. The head suspension includes a load beam to apply load onto the head including the slider.
The hard disk drive usually employs a load-unload technique to retract the slider out of the tracks of the hard disk when the hard disk is stopped.
The load-unload technique otherwise known as a ramp-load technique employs a ramp block made of synthetic resin and arranged at a side of the hard disk. When the hard disk is stopped, the head suspension is moved to a retract position. At this time, a tab corresponding to a guided portion (also called as a load bar, ramp contact, corner, and the like) formed at a front end of the load beam of the head suspension slides along a slope of the ramp block, to separate the slider away from the hard disk.
The head suspension must be light to improve antishock performance and the load beam must be thin to reduce the weight of the head suspension. To meet these requirements, the rigidity of the tab formed at the front end of the load beam tends to be decreased.
The rigidity of the tab, however, must be maintained even if the load beam is made thinner. For this, Japanese Unexamined Patent Application Publication No. 2005-166203 discloses a technique of extending a box-bent portion formed along each side edge of the load beam to the tab protruding from the front end of the load beam.
This related art, however, causes an outward projection to be formed at a portion of the load beam making the transition to the tab side when forming the box-bent portion. The outward projection interferes with a metal mold and produces droppable burrs due to the interferer. The droppable burrs may damage a hard disk drive in which a head suspension having the load beam is installed. A cause of the outward projection results the structure of the load beam consisting of a body, a slope formed by bending a front portion of the body along a bend line, and the tab extending from the slope. Accordingly, when each edge of the load beam up to the slope is box-bent, a portion of the box-bent portion corresponding to the edge at the bend line deforms to cause the outward projection (excessive projection) due to material surplus.
A similar related art will be found in Japanese Unexamined Patent Application Publication No. 2005-116129.